Lead in teeth can tell a body’s tale
Your teeth can tell stories about you, and not just that you always forget to floss.
A study led by University of Florida geology researcher George Kamenov showed that trace amounts of lead in modern and historical human teeth can give clues about where they came from. The paper will be published in this month’s issue of Science of the Total Environment.
The discovery could help police solve cold cases, Kamenov said. For instance, if an unidentified decomposed body is found, testing lead in the teeth could immediately help focus the investigation on a certain geographic area. “We can use this pollution signal to figure out where these people came from,” he said.
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Lead is composed of four variants, called isotopes. The amount of those isotopes fluctuates in different rocks, soils and ores – and, therefore, regions of the world. Mining and other pollution-causing activities release that lead into the environment, and it accumulates in children’s bodies as they grow because kids inhale dust and ingest soil when they put their hands in their mouths.
Tooth enamel, which develops during childhood, locks in the lead signals and preserves them.
“When you grow up, you record the signal of the local environment,” Kamenov said. “If you move somewhere else, your isotope will be distinct from the local population.” news.ufl.edu
Biomimicry in butterflies in 6 generations
Yale University scientists have chosen the most fleeting of mediums for their groundbreaking work on biomimicry: They’ve changed the color of butterfly wings.
In so doing, they produced the first structural color change in an animal by influencing evolution. The discovery may have implications for physicists and engineers trying to use evolutionary principles in the design of new materials and devices.
The research appears in the journal Proceedings of the National Academy of Sciences.
“What we did was to imagine a new target color for the wings of a butterfly, without any knowledge of whether this color was achievable, and selected for it gradually using populations of live butterflies,” said Antónia Monteiro, a former professor of ecology and evolutionary biology at Yale, now at the National University of Singapore.
In this case, Monteiro and her team changed the wing color of the butterfly Bicyclus anynana from brown to violet. They needed only six generations of selection.
Little is known about how structural colors in nature evolved, although researchers have studied such mechanisms extensively in recent years. Most attempts at biomimicry involve finding a desirable outcome in nature and simply trying to copy it in the laboratory. yale.edu
‘Shark Week’ back for 26th year
Celebrating “Shark Week?” Discovery Channel sure is. Since 1988, the cable TV station has given over a full summer week to the toothy, feared (and often misunderstood) fish species. It began Sunday, continues through Saturday and features 11 shark-filled specials. It’s a 24/7 undertaking: Shows debut in the evening and are repeated. Get the details at http://bit.ly/1txVR6I, where you can also see monitor five “shark cams,” watch shark videos, learn shark facts, play a game and take a quiz. Staff Reports